Biodegradable Tea and Coffee Wrapper and Tag

ABSTRACT

A tea and coffee bag wrapper and tag is shown with improved properties than current state of the art wrappers and tags. The novel tea bag and coffee bag tags and wrappers are non-GMO and fully compostable in about 30 days. Unlike other tags and wrappers that can remain in a compost for years, the present tags and wrappers completely biodegrade within 30 days. In one aspect, a PLA mono-component fiber is utilized at a specific blend ratio of L and D PLA structure. The manufacture of the same is also disclosed.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority from U.S. provisional application No.62/813,094 filed Mar. 3, 2019, the disclosure of which is herebyincorporated herein by reference.

FIELD OF USE

The present disclosure relates to a biodegradable beverage wrapper andtag, and more particularly to the manufacture of a tea coffee bag tagand related wrappers that is non-GMO and fully compostable.

BACKGROUND OF THE INVENTION

With the proliferation of biodegradable and recycled materials, there isa need for a substrate, particularly for tea and coffee wrappers andtags, which provides for 100% bio-degradable and does not contain anyinert or non-biodegradable components.

The tea hag was invented by accident more than 1.00 years ago by anAmerican merchant Thomas Sullivan, who decided to send samples of tea tocustomers in small silk pouches. Some people were confused—assuming thatthe bags were supposed to be dunked in hot water just like traditionalmetal tea infusers. When Sullivan heard what they were doing, he spotteda gap in the market. Thus, serendipitously, the tea bag was born.

At first, there were complaints that the mesh of the bags was too fine,so he replaced the silk with gauze. And as tea bags entered massproduction, cheaper paper was used instead. Tea drinkers were reluctantto abandon loose leaf tea, but by the 1950s, when families wereembracing new labor-saving gadgets like never before, tea bags took off.

Bill Gorman, of the UK Tea Council, credits the tea bag with saving thetea industry. “We would not be drinking the volume of tea we do nowwithout them,’ he says—and he would know. “The UK is the second-largesttea market per person in the world. Ireland is first. Without tea bags,the industry would be on its knees.”

Major brands such as PG Tips and Tetley no longer use wood pulp to maketheir paper, but a vegetable fibre derived from the abaca plant—arelative of the banana grown mostly in Indonesia and South America.However, according to the Tea Council, tea companies certainly use a lotof it —, around 96 percent of the tea made is with tea bags.

It adds up to a lot of paper, particularly when so many tea bags are nolonger rectangular—the least wasteful design for a tea hag—but round orpyramid-shaped. A PG Tips pyramid bag, for instance, is made from arectangle of perforated filter paper approximately 70 cm square. Atraditional square tea bag, on the other hand, uses around 50 cm squareof paper.

It is estimated that tea drinkers in Britain alone throw out 370,000tons of tea bags and tea leaves each year, along with vegetablepeelings, onion skins and coffee grinds. Most of this ends up inlandfill sites. The environmental impact of tea bags could easily hereduced if people simply threw the bags on the compost heap or flowerbeds. But it's not that simple. For while most of a tea bag is made frombiodegradable paper, around 2.0 to 30 percent is not made ofbiodegradable material.

In order to stop tea bags bursting open in transit or in the cup, manyare sealed with a strip of heat-resistant polypropylene plastic. Thatplastic doesn't compost, even after a few years, and gardeners oftenfind these small plastic meshes amid their homemade compost (along withthose non-biodegradable stickers that are found on fresh fruit such asapples). In addition wrappers and tags of the tea don't readilybiodegrade.

There have been attempts to solve this issue that has been met withlimited success. U.S. Pat. No. 8,828,895 describes a method of makingfilter fabrics by utilizing mono-component, mono-constituent fibers madefrom both high and low melt temperature Polylactic Acid (PLA) fibers.U.S. Pat. No. 9,998,205 describes the use of mono-component PLA fiberscombined with PLA powders also have the ability to remove chlorine fromdrinking water. Both patents describe string made from mono-component,mono-constituent PLA fibers.

But, there appear to be no tags or wrappers that are non-GMO andbiodegradable in normal composting, and made from a renewable resource.Most wrappers are made from plastic film or foils that are made plasticsor metals.

Thus, there remains a need in the art for a process and material forcoffee and tea wrappers and tags to completely biodegrade.

SUMMARY

Compared to the above methods the present disclosure fulfills the abovecriteria and provides additional benefits that state of the art systemscannot provide.

The current apparatus and method provides for a polylactic acid (PLA)that is a polymer that acts very much like polyester (PET) but isbiodegradable thermoplastic aliphatic polyester and is made fromrenewable resources, such as corn starch, beets, and sugar cane. Mostproducers use Genetically Modified Organism (GMO) in the crops such ascorn, beets, and the like as the feed stock for PLA.

Total-Corbion uses sugar cane from Thailand that is required to benon-GMO. The sugar cane is converted into sugar that can be fermented toform PLA. PLA can be produced in both a L or D configuration. The L formhas a higher melt point. By combining the D & L forms duringpolymerization, the melting point can be lowered and controlled at aspecified melt temperature.

Polymerization of a racemic mixture of L- and D-lactides usually leadsto the synthesis of poly-DL-lactide (PDLLA), which is amorphous. Use ofstereospecific catalysts can lead to heterotactic PLA which has beenfound to show crystallinity. The degree of crystallinity, and hence manyimportant properties, is largely controlled by the ratio of D to Lenantiomers used, and to a lesser extent on the type of catalyst used.Apart from lactic acid and lactide, lactic acid O-carboxyanhydride(“lac-OCA”), a five-membered cyclic compound has been used academicallyas well. This compound is more reactive than lactide, because itspolymerization is driven by the loss of one equivalent of carbon dioxideper equivalent of lactic acid.

Due to the chiral nature of lactic acid, several distinct forms ofpolylactide exist: poly-L-lactide (PLLA) is the product resulting frompolymerization of L,L-lactide (also known as L-lactide).

It is well know that PLA polymers range from amorphous glassy polymer tosemi-crystalline and highly crystalline polymer with a known glasstransition 60-65° C., a melting temperature 130-180° C., and a tensilemodulus 2.7-16 GPa. Heat-resistant PLA can withstand temperatures of110° C. The basic known mechanical properties of PLA are between thoseof polystyrene and PET. It is also known that the melting temperature ofPLLA can be increased by 40-50° C. and its heat deflection temperaturecan be increased from approximately 60° C. to up to 190° C. byphysically blending the polymer with PDLA (poly-D-lactide). PDLA andPLLA form a highly regular stereocomplex with increased crystallinity.The temperature stability is maximized when a 1:1 blend is used, buteven at lower concentrations of 3-10% of PDLA, there is still asubstantial improvement. In the later case, PDLA acts as a nucleatingagent, thereby increasing the crystallization rate. Biodegradation ofPDLA is slower than for PLA due to the higher crystallinity of PDLA. Theflexural modulus of PLA is higher than polystyrene and PLA has good heatsealability.

In one aspect, a non-woven fabric composition web of mono-component,mono-constituent PLA fiber composition consisting of: a mono-component,mono-constituent polylactic acid (PLA) fiber. The polylactic acid (PLA)fiber has different deniers and blend percentages of high and low meltfibers. The fibers, in one embodiment, have a melt flow temperature in arange of 145-175° C. and 105-165° C., for high melt flow fibers and lowmelt flow fibers respectively.

Any combination and/or permutation of the embodiments is envisioned.Other objects and features will become apparent from the followingdetailed description considered in conjunction with the accompanyingdrawings.

It is to be understood, however, that the drawings are designed as anillustration only and not as a definition of the limits of the presentdisclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The patent or application file contains at least one drawing executed incolor. Copies of this patent or patent application publication withcolor drawing(s) will be provided by the Office upon request and paymentof the necessary fee.

To assist those of skill in the art in making and using the disclosedcomposition and method, reference is made to the accompanying figures,wherein:

FIG. 1 shows a photomicrograph of the material used for a beverage tagand wrapper in accordance with one embodiment of the present disclosure;

FIGS. 2A-2B illustrate the front and back, respectively, of oneembodiment of a wrapper, and illustrating that color design may beutilized.

DETAILED DESCRIPTION

U.S. Pat. No. 8,828,895 describes methods to select a percentage of hightemperature PLA blended with a low temperature PLA. The presentinvention is unlike bi-component fibers that have a specific percentageof high temperature polymer in a core and percentage of low temperaturepolymer on a sheath. This arrangement limits the ability to provide anintimate blend of fibers that can be adjusted for specific physicalproperties.

By using mono-component, mono-constituent fibers, the diameter, length,fiber shape, and melt temperature can be adjusted to achieve thatdesired properties. The low melt fiber melts completely and flows andadheres to the high melt fibers as shown in for example in FIG. 1. Asshown, reference number 101 shows a PLA or Co-PLA fiber with a lowmelting point at about 130 C. In this embodiment, the fiber is shownafter calendaring. Reference number 102 shows a PLA fiber in the samecomposition with a high melting point at about 175 C. Note that thesedifferent melting points are not a core fiber and a surrounding sheathfiber as previously known in the art.

While the US patent U.S. Pat. No. 8,828,895 provided for media up to 55grams/square meter (gsm), tags and wrapping require heavier weights toobtain the strength and stiffness required. Thus this patent is notuseful for tags or wrappers.

It was found in the present invention that by regulating the percentageof low melt fibers and processing conditions, the various properties ofthickness, porosity, tensile strength and elongation can be controlled.

The following Examples further describe this material and process. Thebelow examples are given merely to show how the invention may beimplemented and in no way limits the invention to any particularembodiment.

Example 1

Initial production was produced with the following blend:

85% PS2438 1.5d×2.0″ High Melt—170-175° C. Melt Point

15% PS 2971 2.5d×1.5″ Low Melt—130° C. Melt point

The production line had 3 carding machines 2.5 m wide equipped withrandomizer rolls to orient the fiber approximately 2:1 machinedirection: cross-machine direction.

The webs were deposited on a continuous apron and the web was fed into atwo-roll calendar heated at 140 C producing a nonwoven fabric in widthsup to 2.5 meter wide. Other lines are capable of producing up to 5.5 mwide.

The product was produced at 40 gsm. While, this was acceptable forcoffee or dusty product pouches, it did not have adequate strength andporosity needed for tags or wrapping.

Example 2

The next production run utilized a shorter Low melt fiber with the hopeof achieving better dispersion.

85% PS2438 1.5d×2.0″ High Melt—170-175° C. Melt Point

15% PS 2971 2.5d×1.0″ Low Melt—130° C. Melt point

The product was run on the same production line at 40 gsm. The resultwas far better dispersion of the low melt fiber, but a marginalimprovement of physical properties.

Example 3

At this point, a change of fiber manufacturing line was chosen to makemore uniform fibers with less shrinkage to improve web quality andfaster production rates.

The fiber blend was also changed to achieve a stronger and stiffer web.The new blend was:

80% NwN Type 490 1.7 dTex (1.5 denier) PLA×50 mm (2″) (Melt point 170°C.)

20% NwN Type 460 2.5 dTex (2.25 denier) PLA×38 mm (1.5″) (Melt point135° C.)

The product was run at 40 gsm, but the strength increased by 80% and thestiffness was much improved.

Example 4

The next production run was established at an increased weight of 60 gsmand an increased binder level:

77% NwN Type 490 1.7 dTex (1.5 denier) PLA×50 mm (2″) (Melt point 170°C.)

23% NwN Type 460 2.5 dTex (2.25 denier) PLA×38 mm (1.5″) (Melt point135° C.)

The result was a very strong product at 60 gsm that was suitable forprinting and slitting for tags and wrappers.

The product was slit at 255 gsm and was printed at an established labelcompany. Logos were developed and printed on the 60 gsm product as shownin FIG. 2A and FIG. 2B. Also illustrated in FIGS. 2A-B is the abilityfor the biodegradable material to be printed in color. Biodegradableinks may be utilized to further the biodegradability of the wrappers andtags. Printability on the biodegradable formulation was shown to holdfine detail and color images unlike other biodegradable mixtures in thepast.

In one aspect, when the tags are made of the same components as thefilter media and string described in U.S. Pat. No. 8,828,895, all threeproducts (filter, string, and tag) can be attached to each other usingultra-sonic sealing at very high speeds.

It was determined that a fabric with a weight greater than 50 gsm wassuperior for stiffness, tensile strength, and opacity. The best weightrange is from 55 to 120 gsm.

The wrapper material is 60 gsm and can be printed with normal printingequipment and slit to the desired width. It seals easily with bothcontrolled heated platens or with ultrasonics.

Trials were performed on a pilot basis to increase the percentage of lowmelt, mono-component, mono-constituent fibers. The result was increasedstiffness, increased strength and less opacity. This appears to behelpful to improve the clarity of the tea and coffee bags.

Fibers that are finer denier such as 0.6 to 1.4 denier will allow forgreater opacity and better coverage, but may sacrifice strength. Fibersthat are coarser such as 3 to 6 denier may be stronger but may result ismore holes and less coverage.

Further, increasing the binder content appears to decrease the airflowand may allow the production of wrapping material with controlledairflow to prevent the intrusion of undesirable materials such as mold,mildew, fungus or bacteria through the wrapping into the material insidethe wrapping.

Further, this increased binder level can be adjusted to allow moistureto escape from the material inside the wrapper.

Depending on the embodiment, the wrapper may be used for meat,vegetables, fish, candy, cheese, or any foodstuff where controlledbreathability, printability, and rapid biodegradability are desirable.

The tag and wrapper go completely clear when wet allowing the materialinside to be seen clearly. Since the wrapper can be sealed with heat orultrasonics, this eliminates the need for sealing tape.

Additionally, Titanium Dioxide may be added to the fibers to increaseopacity. Other pigments such as Phthalo Blue, Phthalo green, yellowochre, iron oxide, or other color fast pigments may be used to havecolors that are water fast and withstand fading in sunlight.

The printing could use vegetable dyes or the fabric could be fullycolored with vegetable dyes to remain organic and completelycompostable.

Finally, an impermeable film of PLA or other plastic such as PE, PP,PET, or polyamide can be laminated to the wrapping to prevent airflow ineither direction of the wrapping material.

The following aspects were found possible utilizing the teachings of theinvention. A non-woven fabric composition web for a tea or a coffeewrapper and tag consists of a tea or a coffee wrapper and tag having aplurality of mono-component, mono-constituent polylactic acid (PLA)fibers and a pigment. The polylactic acid (PLA) fibers as describedherein have different deniers and a blend percentages of a high melt PLAfiber and a low melt PLA fibers with a melt flow temperature in a rangeof 145-175° C. and 105-165° C., respectively. Again, the tea or thecoffee wrapper and tag are non-GMO and fully compostable in about 30days. In one aspect, the fibers have a weight range from 55 gsm to 150gsm. In another aspect, the fibers have a weight range from 55 to 75gsm. The fibers have a percentage of a high melt fiber ranging from 55%to 95% and a percentage of a low-melt fiber ranging from 5% to 45%.Depending on the embodiment, the fibers may also have a denier rangingfrom 0.7 to 6.0 denier. The fibers may also have a length that rangesfrom 12 mm to 130 mm Fiber denier ranges from 1.5 to 2.5 denier as alsoachievable using the principles of the present invention. The fibers mayalso have a length that ranges from 25 mm to 51 mm Depending on theembodiment, the pigment used with the fibers is a titanium dioxidepigment for making the non-woven fabric composition opaque in color. Thepigment may also be a color fast pigment selected from a groupconsisting of Phthalo Blue, Phthalo Green, iron oxide, Yellow Ochre, andany combination thereof. Depending on the embodiment, the pigment isadded to either the low melt PLA fiber, the high melt PLA fiber, or boththe low and the high melt PLA fibers to provide a colored fabric. Thetea or the coffee wrapper and tag are printable with text, drawings, orlogos in biodegradable colored ink or other ink that bio grades well.The wettability for the material used for the tea and coffee wrappersand tags is sufficient so that fine designs on the wrapper and tag donot bleed off and keep their detailed form and color. The compositionfor the tea or the coffee wrapper and tag may also be used for wrappingmeat, vegetables, fish, candy, cheese, or foodstuff to providecontrolled breathability and rapid biodegradability.

Any headings and sub-headings utilized in this description are not meantto limit the embodiments described thereunder. Features of variousembodiments described herein may be utilized with other embodiments evenif not described under a specific heading for that embodiment.

Although the invention herein has been described with reference toparticular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and applications of thepresent invention. It is therefore to be understood that numerousmodifications may be made to the illustrative embodiments and that otherarrangements may be devised without departing from the spirit and scopeof the present invention as defined by the appended claims.

While exemplary embodiments have been described herein, it is expresslynoted that these embodiments should not be construed as limiting, butrather that additions and modifications to what is expressly describedherein also are included within the scope of the invention. Moreover, itis to be understood that the features of the various embodimentsdescribed herein are not mutually exclusive and can exist in variouscombinations and permutations, even if such combinations or permutationsare not made express herein, without departing from the spirit and scopeof the invention.

What is claimed is:
 1. A non-woven fabric composition web for a tea or acoffee wrapper and tag consisting of: a tea or a coffee wrapper and taghaving a plurality of mono-component, mono-constituent polylactic acid(PLA) fibers and a pigment; the polylactic acid (PLA) fibers havingdifferent deniers and a blend percentages of a high melt PLA fiber and alow melt PLA fiber having a melt flow temperature in a range of 145-175°C. and 105-165° C., respectively; and wherein, the tea or the coffeewrapper and tag are non-GMO and fully compostable in about 30 days. 2.The non-woven fabric composition in claim 1, wherein the fibers have aweight range from 55 gsm to 150 gsm.
 3. The non-woven fabric compositionin claim 1, wherein the fibers have a weight range from 55 to 75 gsm. 4.The non-woven fabric composition in claim 1, wherein the fibers have apercentage of a high melt fiber ranging from 55% to 95%, and apercentage of a low-melt fiber ranging from 5% to 45%.
 5. The non-wovenfabric composition in claim 1, wherein the fibers have a denier rangingfrom 0.7 to 6.0 denier.
 6. The non-woven fabric composition in claim 1,wherein the fibers have a length that ranges from 12 mm to 130 mm. 7.The non-woven fabric composition in claim 1, wherein the fibers have adenier ranging from 1.5 to 2.5 denier.
 8. The non-woven fabriccomposition in claim 1, wherein the fibers have a length that rangesfrom 25 mm to 51 mm.
 9. The non-woven fabric composition in claim 1,wherein the pigment is a titanium dioxide pigment for making thenon-woven fabric composition opaque in color.
 10. The non-woven fabriccomposition in claim 1, wherein the pigment is a color fast pigmentselected from a group consisting of Phthalo Blue, Phthalo Green, ironoxide, Yellow Ochre, and any combination thereof, and wherein thepigment is combined with either the low melt PLA fiber, the high meltPLA fiber, or both the low and the high melt PLA fibers to provide acolored fabric.
 11. The non-woven fabric composition in claim 1, whereinthe tea or the coffee wrapper and tag are printable with text, drawings,or logos in biodegradable colored ink.
 12. The non-woven fabriccomposition in claim 1, wherein the composition for the tea or thecoffee wrapper and tag is used for wrapping meat, vegetables, fish,candy, cheese, or foodstuff to provide controlled breathability andrapid biodegradability.